Norma Marion Alloway Library

Evidence Synthesis: Nursing

Use this guide as a resource for your evidence synthesis research.

Primary Sources

There are two main categories of research evidence: primary and secondary.

Primary research is conducted, analyzed, and reported directly by the researcher.

Common sources of primary research in health sciences are clinical trials or randomized controlled trials (RCTs).

These are some of the more commonly-used health-sciences databases. For an extensive list, see the Article Databases page.

Narrowing search results to primary studies

You can often select a limiter within a database to narrow your search results to clinical trials or RCTs. Look for an option that refers to Publication Type.

Effective Database Communication

Keyword searching:

Google may understand what you mean when you query "effective methods of toileting adults with upper-spinal-cord trauma," but a database will not. Instead, you need to break your question down: ( toileting AND adult AND "spinal cord trauma" ).

Identify the main elements of your question, and search using the same language that an author might use when referring to those topics. The more synonyms you can come up with for your initial search terms (eg. "spinal cord trauma" or "spinal cord injury") the more successful your keyword search will be. Examine any relevant articles you come across for additional language that you can use in your search.

 

 

 

 

 

Subject Heading searching:

Subject Headings are contextual, and indicate that an article is about a topic rather than just using that word. For example, if you're looking for resources on culturally-sensitive nursing practice you can use the CINAHL subject heading for cultural sensitivity, and avoid results that are related to microbial and culture sensitivity tests.

 

 

 

Additional search tutorial videos can be found on the Search Tutorials page.

Synthesized Evidence / Secondary Sources

There are two main categories of research evidence: primary and secondary.

Secondary research discusses, analyzes, synthesizes, or otherwise reports on primary research that has already been conducted. Generally, multiple sources of primary research on a related topic are compared within secondary research, allowing the writer to draw conclusions or make recommendations.

Common sources of secondary research in health sciences are systematic reviews or clinical practice guidelines (CPGs).

These are some of the more commonly-used sources of secondary research in the health-sciences.

TRIP database

Use the filters on the left-hand side to narrow your results to systematic reviews, country-specific CPGs, and other forms of secondary sources.

Epistemonikos

Use the category-level filters to select systematic reviews, broad syntheses, or structured summaries.

Effective Database Communication

Here are some tips to focus your search onto secondary sources when searching library databases:

  • If you are searching a database like CINAHL or MEDLINE, that is not specific to synthesized evidence, experiment with adding these kind of keywords and subject headings to your searches:

Keyword searching:

"systematic review*" OR "meta analysis" OR "meta synthesis" OR "metasynthesis" OR "scoping review*" OR "clinic* protocol*" OR "clinical practic*"

 

 

Subject Heading searching:

search your chosen database for headings related to meta-synthesis, systematic reviews, review literature

 

Additional techniques for searching the literature

Citation searching

  • Backward citation searching is the process of looking through the references of a key article to identify additional relevant publications.
  • Forward citation searching is the process of looking for newer research that cites a key article.

For additional information, see the Forward Citation Searching box on the Search Tutorials page.

Hand searching

This is the process of reviewing selected journals manually, looking for any articles that may have been missed during your database searching.

The Cochrane Handbook has an entire chapter on the rationale and techniques for handsearching.

Grey Literature

Grey literature is information produced by organizations that exist for other reasons than to publish, but happen to produce reports, briefs, or other documents. Professional organizations, health authorities, and governmental bodies regularly produce grey literature.

Searching for grey literature can be time-consuming and frustrating, but there are a few basic techniques that can help you get started.

Domain searching:

  1. Focussing on a particular type of site.
  • You can focus a search engine on a particular type of site by telling it to look only at websites with certain endings on the URLs.
  • Common site types are government (.gov.bc.ca, .gc.ca), education (.edu), and organization (.org).
  • To do this, type in your search terms, and then type site:.gc.ca (or the domain you've chosen)

EXAMPLE: "health advisory" site:.gov.bc.ca

  1. Focussing on the content of an individual site.
  • You can use a search engine to search the content of an individual site rather than having to look through it by hand.
  • To do this, type in your search terms, copy the URL of the website you want to search, type site:, and paste the URL

EXAMPLE: prenatal site:https://www.fraserhealth.ca/

Filetype searching:

You can narrow your search to specific filetypes. Searching for PDFs is useful because many grey documents such as reports, white papers, conference announcements, or committee decisions are posted as PDFs.

To do this, type in your search terms, and then type filetype:pdf (you can also specify other types of files, such as doc, xml, ppt)

EXAMPLE: "flu season" filetype:pdf

 

For more detail on searching for grey literature, see the Grey Literature page of the Nursing libguide.

Preprints

Preprints are preliminary reports of work that have not been certified by peer review. They should not be relied on to guide clinical practice or health-related behavior and should not be reported in news media as established information. (MedRxiv, www.medrxiv.org/)

Preprints allow researchers to share information widely and quickly, but should be approached with caution and treated as an unverified source when being included in any literature review.

MedRxiv is a preprint server for health sciences research.

You can access preprints through Ovid MEDLINE by selecting "Ovid MEDLINE(R) Epub Ahead of Print" from the Ovid Gateway to Health Databases.

Be particularly careful when searching Google Scholar to make sure you know what type of content you're accessing. Scholar indexes peer-reviewed papers, theses, preprints, abstracts, and technical reports (https://scholar.google.ca/intl/en/scholar/publishers.html), and the responsibility rests on the researcher to determine which is which. The best way to confirm that an article is a preprint is to open the link to the article and see whether the article has a publication date with a journal, or whether you end up at a non-journal-specific repository.